Title
Solubility of supercritical CO2 in cellulose nitrate with and without ethyl acetate
Authors
YAJUN DING SANJIU YING KEFENG MA and MEILING SUN

Received December 4, 2014
Published Volume 49 Issue 5-6 May-June
Keywords scCO_{2, cellulose nitrate, ethyl acetate, solubility, FTIR}

Abstract
In this paper, the gravimetric method and Fickian diffusion model were utilized to investigate the influence of ethyl acetate on the solubility of supercritical carbon dioxide (scCO2) in cellulose nitrate at different saturation temperatures and pressures, and also the interactions in the scCO2/ethyl acetate/cellulose nitrate system were researched by FTIR. The solubility increased a lot initially, but decreased subsequently with increasing the ethyl acetate content, which could be explained by the different interactions occurring in the scCO2/ethyl acetate/cellulose nitrate system characterized by FTIR. The solubility reached the highest value (26.99 wt%) with 4 wt% ethyl acetate. It was also found that the solubility decreased with increasing the saturation temperature, but increased with increasing the saturation pressure. Meanwhile, the values of sorption and desorption diffusivity were proportional to the amount of CO2 inside the cellulose nitrate matrix.